ITAP20110009A1 - PROCEDURE FOR MAKING SMOOTH, CURLY HAIR, CRESPIUS OR WAVY HAIR BY USING COMBINED USE OF CHITOSAN, ALLANTOIN AND TEMPERATURE DERIVATIVES. - Google Patents

Description

PROCEDURE TO SMOOTH, IN A SEMI-PERMANENT MANNER, CURLY, FRIZZY OR WAVY HAIR BY USING A COMBINED USE OF DERIVATIVES OF CHITOSAN, ALLANTOIN AND TEMPERATURE.

DESCRIPTION

The present patent application for industrial invention relates to a process for making curly, frizzy or wavy hair straight, in a semi-permanent way, based on the combined use of derivatives of chitosan, allantoin and a temperature higher than 170C ,

The structure of the hair fiber (or hair) of the human species is well described in US 6517822B1.

Currently the techniques adopted to make curly or frizzy hair straight can be summarized in three families:

to. Simple conditioning with electric hair straighteners basically consisting of two hot jaws (temperatures above 100 ° C), inside which the hair is grabbed and tightened for modeling in the desired appearance.

b. More mechanical chemical conditioning at low temperature: it makes use of the help of chemical substances If such, placed on the hair and subjected to conditioning at temperatures below 100 ° C, they can induce changes in the appearance of the hair fiber.

c. More mechanical chemical conditioning at high temperature: it makes use of the help of chemical substances to be deposited on the hair and subjected to temperatures above 100 ° C. This technique is able to induce more consistent changes on the hair than those of technique (a) due to the combined action of heat and chemicals placed on the hair itself. In the treatment of frizzy or curly hair, in order to make it smooth, numerous chemical substances are currently used that are capable of interacting with the disulfide bridges of cystine or with peptide bonds of the amino acids making up the hair fiber. These treatments are well described for example in WO 2007/135299 A1 and in US 2010/0300471 A1. The substances used for this type of treatments present in most cases problems of high toxicity towards man and / or high aggressiveness towards the hair (eg: formic aldehyde, glutaraldehyde, sodium hydroxide, ammonia, sulfur compounds, guanidine etc) .

There are numerous patent documents relating to the use of glyoxylic acid in the treatment of hair to improve their visual appearance and their physical-mechanical characteristics.

GB 1416564 A uses mercaptoderivatives to obtain the permanent deformation of the hair based on the principle of breaking the disulfide bridges of the cystine using in the mixture also salts of glyoxic acid (and not glyoxic acid) with evident action of agent buffer of pH. The declared concentrations of glyoxic acid salts are all lower than 4% by weight (our invention foresees a range of use between 4.5 and 14.5% of glyoxic acid) and also the procedure described in GB 1416564 A excludes the use of temperatures above 150 <°> C.

US 6086861 uses glyoxylic acid and its salts for the treatment of hair dandruff

WO 2007/135299 and FR 2901472 describe a method for stretching keratinous fibers using high temperature and particular families of carboxylic acids (alpha-hydroxyl and alpha-ketone) and their derivatives. This document does not include glyoxylic acid among the substances whose protection is requested.

The object of the present invention is to eliminate the drawbacks of the known techniques, providing a process for making the hair smooth that is efficient, effective and lasting over time for at least six washes.

Another object of the present invention is also to provide such a process for making the hair smooth which is not harmful to the hair and to the health of the person applying it.

These purposes are achieved in accordance with the invention, with the characteristics listed in the attached independent claim 1. Advantageous embodiments appear from the dependent claims. The object of the invention is a process based on the combined use of particular imine derivatives of chitosan and of € ™ allantoin and a high temperature mechanical treatment.

Unlike what is shown by the state of the art, with the procedure according to the invention, from curly and / or frizzy hair you get straight, soft, shiny hair (and with a strong reduction in volume in the case of frizzy hair), which maintain these characteristics even after repeated washing with water and shampoo (semi-permanent effect),

The process according to the invention modifies the spatial conformation of the capillary fibers, reducing the volume occupied and the number of curves.

The process according to the invention involves the combined action of imine derivatives of chitosan, allantoin derivatives (dissolved in water or in combination with one or more of the commonly used cosmetic ingredients described in the European Commission Decision of 8 May 1996 published in the Official Journal of the European Community L 132 of 01/06/1996), and of a mechanical ironing with a hair straightener at a temperature of about 200 <°> C (+/- 30 ° C). This procedure makes it possible to modify the shape of the hair fiber so that it, if originally curly and / or frizzy, acquires a smooth shape and maintains it for at least six successive washes of the hair.

More precisely, the procedure includes the following phases:

- application on the hair fibers of imine derivatives of chitosan and allantoin;

- permanence of the substances in contact with the hair for a time between 30 and 120 minutes:

- hair drying;

- hair straightening with a hair straightener, placed at a temperature of about 200 ° C (+/- 30 ° C) degrees centigrade.

In particular, the process according to the invention has been shown to be capable of inducing semi-permanent changes in its shape in the hair, which remain so even after repeated washing of the hair itself in the conditions of common use. Further characteristics of the invention will appear clearer from the detailed description that follows, referring to a purely exemplary and therefore non-limiting embodiment thereof.

Chitosan derivatives are well known for their beneficial properties on the hair. As many as 183 patents on this substance are available by consulting the ESPACENET database of the European Patent Office (EPO).

The formation of imine derivatives of chitosan is well known in the literature and in particular the article by Prof. Riccardo Muzzarelli N-carboxymethylidene) chitosan and n- (carboxymethyl) chitosan: novel chelatìng polyampholytes obtainer from chitosan glyoxylate "published in Carbohydrate research Vo. 107 (1982) 199-214 fully describes its preparation methods and characteristics, The imine derivative of chitosan called â € œN- (carboxymethylidene) chitosanâ € is easily obtained by simply mixing chitosan with glyoxylic acid, Lâ € ™ allantoin is It is a substance widely used in cosmetics and there is an impressive amount of patents that specify the methods of use. WO2010EP57544 gives a summary. it limits its application in cosmetic products (it is usually used in the form of solid suspensions on a water basis although less active). It can be augmented using urea derivatives as described in US2008081052 <A1) and US2008057002 (A1).

Surprisingly we have found that when allantoin comes into contact with an aqueous solution of glyoxylic acid, it dissolves completely when hot up to an amount equal to! stoichiometric ratio between glyoxyic acid (molecular weight 74.04) and allantonia (molecular weight 158.12).

Allantoin cannot be separated from this solution by modification of the pH, the solution remaining clear from pH 1.5 to pH 12. Even the decrease in temperature does not involve the separation of alantoin from the solution which , even if frozen at -20 ° C, when it is brought back to room temperature no separation of allantoin from the solution is observed. These data show that mixing allantoin and glyoxyic acid together does not obtain their hydrolytic salt (ailantoin glyoxylate), but a base of Schifi {-N-C-), which behaves in a completely unexpected compared to the characteristics of the initial substances.

The repeated preparation of 100 and more aqueous solutions of allantoin in glyoxyic acid, while hot, has always provided the same results: a clear final solution, which remains so even after cooling, and after raising the pH.

Having ascertained this discovery, considering that both chitosan and allantoin have a free amino group (NH2) in their molecules, it is reasonable to assume that this functional group, which in the case of chitosan has been shown to react by forming a carboxyme group ¬nico (-N = C-COOH), in the presence of glyoxylic addus, behaves in a similar way to allantoin, with the formation of the corresponding Schifi base N- (carboxymethylidene) allantoin. The preparation of 100 solutions of chitosan (various concentrations) in glyoxic acid produced 100 clear solutions.

Following the first discovery, and on the basis of this last consideration, and its result, solutions and mixtures of the two substances were made with glyoxic acid. 100 attempts with varying concentrations produced 100 clear solutions of allantoin and chitosan in diluted glyoxic acid. Having ascertained this, we proceeded to verify the performance of the solutions thus obtained in the semi-permanent conditioning of the hair fibers.

Some examples of the composition of solutions are reported below: Example 1;

â € ¢ N- (carboxymethylidene) chitosan (obtained by dissolving 1.0 grams of chitosan in 1.0 grams of glyoxic acid)

â € ¢ Acidulated water at pH 2 with glyoxic acid as required for 100 grams

Example 2

â € ¢ N- (carboxymethylidene) Allantoin (obtained by dissolving 1.0 grams of allantoin in 1.0 grams of glyoxic acid)

â € ¢ Acidulated water at pH 2 with glyoxic acid as required for 100 grams

Example 3

â € ¢ N- (carboxymethylidene) chitosan (obtained by dissolving 1.0 grams of chitosan in 1.0 grams of glyoxylic acid)

â € ¢ N- (carboxymethylidene) Allantoin (obtained by dissolving 1.0 grams of allantoin in 1.0 grams of glyoxyl acid)

â € ¢ Water acidulated to pH 2 with glyoxylic acid as required for 100 grams

Example 4

â € ¢ N- (carboxymethylidene) chitosan (obtained by dissolving 1.0 grams of chitosan in 1.0 grams of glyoxylic acid)

â € ¢ N- (carboxymethylidene) Allantoin (obtained by dissolving 1.0 grams of allantoin in 1.0 grams of glyoxyl acid)

â € ¢ Cetrimonium chloride 1.0 grams

â € ¢ Citric acid 0.5 grams

â € ¢ Water acidified to pH 2 with glyoxylic acid as required for 100 grams

The mixtures of these 4 examples contain substances of common use in cosmetics, listed in the databases of the European Community Legislation (Cosing) among those whose use in cosmetic products is allowed without any restriction of use, because they are harmless for the human health. For 6 months we tested the performance of 100 of each of these 4 solutions on the hair of volunteers (100 volunteers for each type of prepared solution). These solutions were placed in contact with the hair fibers previously washed with shampoo according to normal use. These solutions were then applied to the head fibers with the aid of a stiff bristle brush.

The capillary fibers have been covered with a plastic cap to reduce the evaporation of water and the solutions indicated above are left in contact with you for a time of 30, 60 120 minutes, after which they have been dried with a hairdryer according to the common use.

Once dried, the capillary fibers were subjected to ironing using a hair ironing plate, heated to an average temperature of about 210 degrees centigrade.

Finally, the hair fibers were subjected to subsequent washing with shampoo and drying.

At the end of the treatment the hair fibers were shiny, smooth, soft to the touch, and with a particularly pleasant overall appearance.

The effectiveness of the treatment according to the invention (solutions n. 3 and n.

4), in the modification of the shape of the hair fiber, it has been shown to be stable over time on average for eight washes, rinses and dryings under normal conditions of use of hair shampoo, but in European, natural, curly hair. € ™ smooth, shiny and soft effect lasted for an average of 16 washes.

In â € œAfro "hair, the performance of solutions No. 3 and No. 4 is better if the contact time of the capillary fibers with the mixtures is extended to 120 minutes (see results in table 5).

The results of the tests performed are shown in the following tables from 1 to 5 (each result is the average of 100 results obtained).

Table 1

HAIR type "AFRO" NATURAL CURLY EVALUATION SMOOTHING EFFECT {curves reduction)

PREPARATION SUBJECT TO TEST

WATER 100 ml 30 60 210 H (-> Mixture Example 1 30 60 210 (<+++ >> {+++) (Mixture Example 2 30 60 210 <+++) {+++) (Mixture Example 3 30 60 210 (+++) {+++) Mixture Example 4 30 60 210 (<+++>) ^

Reduction Reduction Reduction No reduction Red MEASURED PARAMETER between 26 and between 51 and between 76 and the minor effect> 50% 75% 90% 25%

% Reduction in the number of curves found on 30 crn di

hair (no. residual curves / no. initial curves x 100) - / - + ++ Table 2

HAIR type "AFRO" NATURAL CURLY VOLUME REDUCTION EVALUATION (reduction in space size hair

PREPARATION SUBJECT TO TEST

WATER 100 ml 30 60 210 <-) <-) {-) Mixture Example 1 30 60 210 (+++) (+++) () Mixture Example 2 30 60 210 (+++) (+++) ( +++} Mixture Example 3 30 60 210 (+++) (<+++>) (+ #) Mixture Example 4 30 60 210 (+++) (+++)

No reduction Reduction Reduction MEASURED PARAMETER lesser effect between 26 between 51 between 76 and Reduction of 25% and 60% and 75% 90%> 90% Reduction of hair volume (circumference of a

strand weighing 1.0 grams measured at the middle of the / - + ++ +++ length) (end test diameter / initial diameter x100)

Table 3

HAIR type "European" NATURAL CURLY EVALUATION SMOOTHING EFFECT (curves reduction)

EPARATE SUBJECTED TO TESTa s

WATER 100 ml 30 60 210 R R R Mixture Example 1 30 210 (++ Mixture Example 2 30 60 210

Mixture Example 3 30 60 210

Misceta Example 4 30 60 210

Reduction Reduction Reduction

No time Reduction MEASURED PARAMETER reduction

between 26 between

effect 57 between 76 and> 90 and 50% and 75% 90%

25%

% Reduction of the number of curves found on 30 cm

/ - + + <â–> § <â–> ++++ of hair (n curves resìdue / n, initial curves x 100)

Table 4

HAIR type "European" NATURAL CURLY EVALUATION OF VOLUME REDUCTION (reduction of the hair size)

PREPARATION SUBJECT TO TEST

WATER 100 ml 30 60 210 H <-) (-) «-) Mixture Example 1 30 60 210 (+ 4 '++) (+4) (++++) Mixture Example 2 30 60 210 (++++ ) (+++) {++++) (+++

Mixture Example 3 30 60 210 (++++) | + 4 ++ J (++++) {+ <â–> * - +

Mixture Example 4 30 60 210 (++ - M-) (+ ++) (++++) (+++

Reduction Reduction Reduction Reduction

No

MEASURED PARAMETER Minor reduction between 26 and 51 between 76 and

effect> 90 25% 50% and 75% 90%

% Reduction in hair volume (circumference of

a strand weighing 1.0 grams measured in half

/ - + ++

length) (test end diameter / initial diameter +++ xlOO)

Table 5

HAIR type "AFRO" NATURAL CURLY EVALUATION OF SMOOTHING EFFECT (curves reduction) with different times of con

PREPARATION SUBJECT TO TEST

WATER 100 ml 30 30 210 H H (-Ϊ (-WATER 100 ml 30 120 210 (-) (<â–>) (-) {-Mix Example 1 30 30 210 (++++) (<+++> )

Mixture Example 2 30 30 210 (++++)

Mixture Example 3 30 30 210 (++++) (J (+++) Mixture Example 4 30 30 210 (++++} (<+> Mixture Example 1 30 120 210 £ +) ^ F-F-f J

iscela Example 2 30 120 210

Mixture Example 3 30 120 210

Mixture Example 4 30 120 210

Reduction \ Reduction Reduction Reduction

No reduction MEASUREMENT PARAMETER TO less than between 76 and

effect 26 between 51 and

> 25% and 50% 75% 90% 90% Reduction of the number of curves found on 30 cm 44 444 4444 of hair (no. residual curves / no. initial curves x 100) / -

DEFINITIONS

Semi-permanent conditioning: treatment in an acidic environment (pH below 7) of curly or frizzy hair to bring it to a smooth state, and with at least eight washes in this state with water and shampoo, without using substances capable of reacting with disulfide bridges of cystine or by using alkali

Permanent conditioning: treatment of the hair to bring it to the curly or smooth state with permanence in this state for at least eight washes through the use of an oxidation-reduction procedure of the disulfide bridges of the cystine contained in the capillary fibers or by hydrolysis of the peptide bonds with alkali ( pH higher than 7). The technique is well known and described in WO 2007/135299 A1 and US 4409204.

Imine derivative: organic substance containing the functional group (-N = C-).

Carboxyminic derivative: organic substance containing the functional group {-N = C-COOH). This functional group is referred to in English as N- (carboxymethylidene)

Hair straightener: Electric heating device, which is used by associating a combination of heat and pressure to straighten the hair. Generally it consists of two flat heating elements, coated with various materials, between which one lock of hair is pressed at a time. It should be noted that said hair straightening plates are normally available on the market.

Claims (3)

CLAIMS 1) - Process to make the hair fibers of the human species semi-permanently smooth, including the following steps: a) application on the hair fibers of an aqueous solution of N ~ (carboxymethylidene) chitosan b) permanence of the solution in contact with the capillary fibers for a time between 30 and 120 minutes; c) hair drying with a hairdryer; d) hair straightening with a hair straightener, placed at a temperature of about 200 / - 30 degrees centigrade. 2) Process according to claim 1, characterized in that said aqueous solution has a concentration of N- (carboxymethylidene) chitosan comprised between 0.5 and 5%. 3) Process according to claim 1, characterized by the fact that said aqueous solution is part of a cosmetic product containing one or more of the substances listed in the European Commission Decision of 8 May 1996 published in the Official Journal of the European Community L 132 of 01 / 06/1996. 4) - Process to make the hair fibers of the human species semi-permanently smooth, including the following steps: e) application on the capillary fibers of an aqueous solution of N- (carboxyhymethylìdene) allantoin. f) permanence of the solution in contact with the capillary fibers for a time between 30 and 120 minutes; g) hair drying with a hairdryer; h) hair straightening using a straightener, placed at a temperature of about 200 / - 30 degrees centigrade. 5) Process according to claim 4, characterized in that said aqueous solution has a concentration of N- (carboxymethylidene) allantoin comprised between 0.5 and 5%. 6) Process, according to claim 4, characterized by the fact that said aqueous solution is part of a cosmetic product containing one or more of the substances listed in the European Commission Decision of 8 May 1996 published in the Official Journal of the European Community L 132 of 01 / 06/1996. 7) - Process to make the hair fibers of the human species semi-permanently smooth, comprising the following steps; i) application on the hair fibers of an aqueous solution of N- (carboxymethylidene) chitosan and N- (carboxymethylidene) allantoin. j) permanence of the solution in contact with the capillary fibers for a time between 30 and 120 minutes; k) hair drying with a hairdryer; L) hair straightening using a straightener, placed at a temperature of about 200 / - 30 degrees centigrade. 8) Process according to claim 7, characterized in that said aqueous solution has a concentration of N- (carboxymethylidene) chitosan comprised between 0.5 and 5% and N- (carboxymethylidene) allantoin comprised between 0, 5 and 5%. 9) Process, according to claim 7, characterized by the fact that said aqueous solution is part of a cosmetic product containing one or more of the substances listed in the Decision of the European Commission of 8 May 1996 published in the Official Journal of the European Community L 132 of 01 / 06/1996,